This invention relates generally to Positron Emission Tomography (PET) systems, and more particularly, to methods and apparatus for loading and storing radioactive source pins used in PET.
Radioactive source pins are used to calibrate PET detector systems. Source pins are also used to provide attenuation during system use or imaging. Because the pins are radioactive, they are stored in a shielded storage device when not in use. The storage device is structurally secure and shields the environment from radiation exposure from the radioactive source pin. The storage device is generally within the PET system. During use the source pin or pins are withdrawn from storage and placed in a rotatable transmission ring within a bore of the PET detector system.
After use, the pin or pins are returned to the storage device. Source pin transport time is a time period between initial removal of the source pin from the storage device to placement in the transmission ring. It is desirable to lessen source pin transport time to reduce potential non-beneficial radiation exposure. Because the shielding requirements limit the placement of the storage device automatic source pin handling is often complex and unreliable. It is therefore desirable to provide methods and apparatus that facilitates quick and reliable handling of the source pin including unloading the source pin from the storage device, transporting the pin and installation of the source pin within the transmission ring.
In one aspect, a method for transporting a source pin in a Positron Emission Tomography (PET) system having a transmission ring is provided. The method includes aligning the transmission ring with a source pin within a storage device having a magnetic force holding the source pin in place, and moving the source pin from the storage device to the transmission ring using a magnetic force greater than the magnetic force of the storage device.
In another aspect, an imaging system is provided. The imaging system includes a rotatable transmission ring, a storage device adjacent the transmission ring, and at least one source pin storable in the storage device. The storage device has a magnetic force holding the source pin in place. The system also includes a source of magnetic force on the transmission ring, the source is configured to move the source pin between the storage device and the transmission ring.
In still another aspect, an imaging system is provided. The system includes a rotatable transmission ring, a storage device adjacent the transmission ring, and a proximity sensor positioned to sense a presence of a source pin in the storage device.
In yet another aspect, a processor is provided. The processor is configured to align a transmission ring with a source pin within a storage device having a magnetic force holding the source pin in place, and move the source pin from the storage device to the transmission ring using a magnetic force greater than the magnetic force of the storage device.
In another aspect, a Positron Emission Tomography (PET) system is provided. The PET system includes a rotatable transmission ring, a storage device adjacent the transmission ring, and at least one source pin. The source pin is storable in the storage device, and the storage device has a magnetic force holding the source pin in place. The system also includes a proximity sensor positioned to sense a presence of the source pin within the storage device, and a source of magnetic force is on the transmission ring, the source is configured to move the source pin between the storage device and the transmission ring.